What I would do is pick out one color from that jacket and then use that color for your pants, that way there will still be contrast but it'll still match and look good (: if you don't want to do that, you could always buy a pair of white pants, that always works too haha

And yeah solid colors are good because your jacket is already so flashy/avoid dark purple because it'll be too murky with it

Personally I would go with the turquoise ish color on the jacket for your pants (: